Help needed

Hello , im looking to buy Good reliable Lifepo4 20S BMS , over the time i have bought some cheap chines (50-80 USD) BMS and they are not reliable at all, the last one i got from Bestechpower and it was ok up until last week it start discharging one of 20 cells for no reason . It looks like that there is no good ones out there or i just can't find them most of them has overcharge protection fo 3.85 which is way to much for A123 20Ah cells .
So can pleas some one advise me where can i buy one , or who makes reliable ones , I dont mind spending few quid.
Thanks allot to all !

I don't use a bms, but this one gets 100% positive feedback, and the price is right. Looks like you can specify voltage you want.
http://www.aliexpress.com/store/product/Free-Shipping-20S-72V-lithium-battery-protection-board-E-bike-Li-ion-LiPo-battery-BMS-30A/313864_1930212978.html

Thanks for reply , but that one has overcharge detection set to 3.85 and it cannot be adjusted. I had to buy 3 new cells after using one BMS like that one .

No, you can have the values set to what specification you want according to the web page.